POTENTIAL USAGE OF THERMOSENSITIVE LIPOSOMES FOR MACROMOLECULE DELIVERY

Since transient swelling during phase transition of liposomes with hyp er-osmotic internal aqueous phase may cause permeation of large molecu les through the lipid bilayer, this type of liposomes can be useful fo r delivering macromolecules. In fact, thermosensitive liposomes contai ning an internal solution with osmotic pressure 2-fold higher than the physiologic level and sized through 200-nm pore, released encapsulate d macromolecules such as dextran (M, 144000) effectively when they wer e incubated at 40-42 degrees C. These liposomes were stable in the pre sence of serum compared to the liposomes with internal osmotic pressur e more than S-fold higher than the physiologic level.